Valves provided with a sleeve for controlling of which the movement is controlled by a thermostatic element typically equip cooling circuits associated with high-capacity heat engines, in particular those used in lorries and certain motor vehicles, for which the flows of coolant required for their operation are higher than those encountered for heat engines with a lower capacity, for which the thermostatic valves used have flaps.
Indeed, using a sleeve in general makes it possible to have a stopper referred to as balanced, i.e. a stopper for which the difference in the pressures on either side of the wall of the sleeve is substantially zero according to the direction of movement of the sleeve by the thermostatic element, with this direction corresponding in practice to the axial direction of the sleeve. Inversely, in a thermostatic flap valve, the latter generally extends in a plane perpendicular to the direction of movement of the flap by the thermostatic element, in such a way that the pressure difference on either side of the flap according to this direction reaches high values, in particular when the circulation of fluid is interrupted by the flap. The energy required to separate such a flap from its seat is therefore often substantial, and this all the more so when the flow of the liquid to be controlled is substantial and flows in the direction of closing of the flap.
That said, current sleeve valves have however limits with regards to their maximum allowable flow. One of the reasons is linked to a poor peripheral supply of the sleeve: although in theory, the entire periphery of the sleeve could be made use of in order to allow the flow of the fluid through this sleeve when the latter is open, it is observed in practice that the flow of fluid supplying the interior of the sleeve is “channeled” through the opening of the inlet opening for this fluid into the housing of the valve. Indeed, when the sleeve is opened, i.e. when the sleeve is separated from its bearing seat defined by a wall of the valve housing, arranged axially across from the sleeve, the fluid tends to transit through the sleeve by entirely and exclusively flowing in the extension of the aforementioned opening. As such, EP-A-1 106 883, on which is based the preamble of claim 1, provides an example of a three-way valve, wherein the sleeve presses, via one of its axial ends, against a wall of the valve housing, separating two circulation ducts of the fluid, between which the fluid tends to transit “in a straight line” when the sleeve is separated from the aforementioned housing wall. The same applies for the valves disclosed in DE-A-44 10 249, U.S. Pat. No. 3,734,405, U.S. Pat. No. 4,022,377, FR-A-2 919 704 and US-A-2002/096571.